The membranes of neurons contain very high concentrations of special phosphoglycerides that are not found in most other cells. These phosphoglycerides contain esterified "omega 3" unsaturated fatty acids that have 6 cis double bonds. The phosphoglycerides probably have a special function, but that function has yet to be defined. They also may contribute to diseases such as Alzheimer's because they are unusually susceptible to oxidation. We have been exploring the possibility that the phosphoglycerides may have unusual packing properties which are required for effective electrical signaling. Molecular modeling studies, done several years ago in our laboratory, raised the possibility that the phosphoglycerides may interact to form regular, tightly packed arrays. However, direct physical evidence in support of this possibility is still lacking. Comparable phosphoglycerides are not commercially available, so we have had to isolate them from native tissues. This has been a very time-consuming process, but we have obtained promising results that are consistent with the kind of tight molecular packing arrangements that were predicted by our models. When completed, our study should increase our understanding of the molecular basis of neuronal conduction.